Method for treating artificial silk obtained from centrifuges



Patented Aug. 4, 1931 UNITED STATES.

PATENT OFFICE LEONHARD MONKEMEYER, OF OBERBRUCH, KREIS'HEINSBERG, GERMANY, ASSIGNOB, BY MESNE ASSIGNMENTS, TO AMERICAN GLANZSTOFF CORPORATION, OF NEW YORK, N. Y.

METHOD FOR TREATING ABTIFICIAL SILK OBTAINED FROM CENTRIFUGES No Drawing. Application filed February 11, .1$27,-8 eria1 No. 167,585,,and in Germany February 13, 1926 In the manufacture of artificial'silk and particularly viscose silk, by the centrifugal process, the method of rocedure which has hitherto been adopted as been to transfer the threads spun into the spinning pot, in the form of a so called cake to a reeling machine where it'is wound into hanks, the hanks so obtained are washed, subjected to centrifugal hydro-extraction and dried, preferably when drying. This unequal stretching takes.

place because in the washing process, the original regular shape of the hanks is frequently lost. Another source of irregularity is found to reside in the fact that in the processes hitherto employed the washed hanks were in-- sufficiently and too unequally washed by means of the usual centrifuges.

According to the present invention these disadvantages are overcome by first washingand centrifuging the silk freshly spun by the centrifugal process, and then reeling it wet, and drying the resulting hanks whilestill intact.

Thorough washing is ensured by vigorously. centrifuging the Washed cake, for which purpose it is caused to rotate both during and after washing while it still remains either in the spinning pot itself or in the pot liner so as to prevent displacement of the threads of the cake. v

The washing of the freshly spun cake cannot be carried out directly, because if this is done the ability of the cake to be reeled oil is generally lost. These cakes can only be reeled off if the threads therein are not stuck together, and also provided that the cake is still so firm that it does not collapse either before or during reeling. Moreover, the va rious threads or layers of threads must not be tangled or pushed through each other, as this causes disturbance when reeling off the yet soft and wet thread.

. According to the present invention, washing ofthe cake without destroying its ability to be reeled off is elfected by rotating it rapply of water-tothe cake, and owing moreover to lthe' instant removal of the water in an outward direction, the thread never has a chance to float, and the positions of the threads are not altered by the finely divided I particles of liquid sprayed upon them,'nor 1s the shape 0 the threads altered, as by a coarse spray used heretofore. The cake therefore does not lose its coherence or shape, I because during this careful washing its coherence is maintained by the action of the centrifugal force.

The washingprocess can be carried to completion ver expeditiously. In order to have the'cake co ere well, and to thoroughly elim-i' inate the last traces of water, the centrifug-' ing is preferably continued for some time afterthe supply of water has been shut off.

Water subdividers or sprinklers of the. pe which spray the water onto the cakeof t tliread practically in the form of mist (that is to say, so-called atomizer nozzles, and in particular, the well known Schlick nozzle) are especially suited for this purpose. Such exceedingly fine subdivision of the water ensures a high degree of protection for the spun cake. Fine subdivision and uniform application of the water 'all over the spun cake are essential, but it is of secondary 1mportance whether this application of finely divided water to the cake e effected by means of pressure, suction, or centrifugal action.

The washing process,'which may be concomitant to the spinning operation, may, if necessary, be carried out onthe spinning machines, that is to say, on the actual spinning spindles themselves, and it has been ascertained that my washing process always lasts a the action of chenncal agents, such as acids,

lyes, salts and the like, which are as a rule used on the spinning machines.

Finally, the gearing of the-washing spindles to the driving parts of the centrifugal machine is undesirable, since the working periods of the washing spindles, their number, and under certain circumstances; even their speed of rotation, may be small in comparison with the corresponding constants of the centrifugal machines. .All these facts are taken into consideration according to the present invention by, providing separate washing spindles or washing out the cakes, and these washing spindles are preferably erected 'uite separate from the spinning machine. he washing spindles allotted to one or more machines may conveniently be. grouped together in the formof a small separate washing machine. The washing machines are driven in a manner similar to that customary for the spinning s indles, either by separate electric motors or y a mechanical transmission, using worms and worm wheels, or by friction or equivalent means.

The washing machines are fitted with the required number of washing sp reception of the. vessels containing the spun cakes and with the driving mechanism reuired therefor, with pipes for the washing uid, nozzles for sprinkling the cake, protective and collecting devices for catching the fluids thrown off, corresponding exhaust and discharge pipes, and, if necessary, any suitable appliances for drawing off gases and vapors evolved.

When washing the cakes, the first wash waters, which contain the ma'or portion of the reagents of the spinning ath adhering to the threads, may be carried off separately, so as to permit the ready recovery of the chemicals, if desired. De-sulphurizing, bleaching or softening reagents may be added to the wash water, or to a portion thereof.

I claim.

A process for the treatment of artificial silk which comprises spinning a cake of thread having a plurality of concentric lay-' ers in a spinningreceptacle, supplying an atomized washing liquid with the cake while in its spinning receptacle and su ported by the outer walls of such receptac e, the inner indles for the walls of the cake supported, and rotating the remaining mechanically unthe receptacle and eliminating com ined by further rotating the rece tacle with the cake, then reeling the threa and finally drying it in hanks.

In testimony whereof I have signed my name to this'specification.

LEONHARD M ONKEMEYER. 

